Levels of natural radioactivity in environment in residential area of Moradabad District, Western Uttar Pradesh

Indoor radon and thoron have been measured in the houses of Moradabad District, Uttar Pradesh India, by means of solid state nuclear track detectors. Radon, an invisible radioactive gas, occurs naturally in indoor atmospheres and along with thoron is the most important contribution of human exposure to natural sources. Radon exists in soil gas building materials and indoor atmosphere to name but a few. Risk of lung cancer depends on the concentration of radon and thoron and their decay products in the environment above recommended levels. The present article measures the concentration of indoor radon and thoron in 60 dosimeters by means of a solid state nuclear track detector in different house types of Moradabad district, Uttar Pradesh. The measurements have been carried out in residential buildings at a height of 2 m from the sea level, using a twin chamber radon dosimeter. The value of radon concentration in the present study varies between 10.5 Bq/m3 and 29.5 Bq/m3 with an average of 19.8 Bq/m3 while that of thoron is between 5.6 Bq/m3 and 24 Bq/m3 with an average of 14.9 Bq/m3 respectively. Results, obtained with twin cup radon/thoron dosimeter, show that the concentration of indoor radon and thoron have been within the recommended level, with all the values staying under the safe limits, decreed by the International Commission on Radiological Protection (ICRP) and United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR).